The present invention relates to a method and apparatus for dispensing and positioning strands of wire or cable and in particular to dispensing wire or cable for forming a bundle and placement of the bundle.
In the construction industry, it is commonly necessary to position a plurality of wires, cables, or the like along similar paths. Typically, the plurality of wires or cables are formed into a bundle and the bundle is put into position such as by pulling it along a desired path.
The process of forming and positioning a bundle is particularly difficult when the individual wires or cables in the bundle must have different starting and/or ending points. FIG. 1A illustrates schematically a bundle, consisting of three wires 10, 12, 14 which are, following positioning, intended to extend between beginning and ending terminals 10a, 10b, 12a, 12b, 14a, 14b, respectively. Because, in the example shown, the beginning and ending terminals 10a, 10b, 12a, 12b, 14a, 14b do not coincide for any of the wires 10, 12, 14, the bundle which is to be pulled along the desired pathway is preferably formed as shown in FIG. 1B. Of particular note is that none of the starting or ending points of the three wires 10, 12, 14 occur at the same point along the bundle 16.
According to previous methods, a bundle such as the bundle 16 shown on FIG. 1B would be formed by extracting each length of wire 10, 12, 14, separately. Typically, the wires 10, 12, 14 would each be pulled from a wire spool, measured, such as with a tape measure, and laid on the surface such as the ground or a floor surface. Next, the three wires 10, 12, 14 would be moved lengthwise, relative to each other, until they had the configuration shown in FIG. 1B. At this point, the wires 10, 12, 14 could optionally be permanently or temporarily held together such as by using cable ties or the like. The bundle 16 thus formed would then be in a configuration such that it could be pulled along the desired pathway.
Once the bundle 16 is formed, it is moved to the initial point of the pathway along which it is to be pulled. Typically, it is moved by pulling or carrying the bundle. Next, the bundle is placed along the desired pathway. According to one method a rope is first placed along the desired pathway, one end of the rope is attached to one end of the bundle and the rope is pulled from the other end, thus pulling the bundle along the desired path. In previous devices, cable was sometimes pulled along a path using a motor. Such motors typically have one or a few rates of pull, making it impossible to accurately adjust the rate of pull to the conditions. Typically, the motor was attached to a portion of the building, such as a beam or a wall. This placed undesirable constraints on where the motor can be positioned so that pulling efficiency was reduced. Pulling efficiency is typically greatest when the pulling apparatus is positioned near one end of the pathway. Because of the need to attach the motor to the building, a large amount of time was required to set up the motor to achieve a pull.
The process of pulling each individual wire, measuring each individual wire, and moving the wires until they have the desired configuration relative to each other is labor-intensive and thus expensive. Furthermore, even when starting or ending points coincide, the process is prone to error, particularly when a large number of wires, such as different gauge wires, are used to form the bundle. Additionally, once the bundle is formed, transporting the bundle to the entry point of the pathway along which it is to be pulled is cumbersome.
In some instances, it has been found useful to position one or more rollers along the desired pathway in order to help guide the bundle as it is being moved. In some cases, it is convenient to form a roller from a length of pipe such as PVC pipe 18 (FIG. 2). In order to provide for axial mounting of the pipe 18, endcaps 20 are press-fitted into the ends of the pipe 18. The endcaps 20 may have hubs 22 for axially mounting the rollers thus formed. The rollers formed according to the configuration shown on FIG. 2, however, have been found to be susceptible to permitting the cable which it supports to slip over the end 24 of the roller, thereby often causing the cable to bind or even damaging the cable.